基于改进重建滤波器的局部CT重建算法  

A Local Reconstruction Algorithm of CT Based on Improved Reconstruction Filter

作　　者：李保磊[1,2] 张耀军[1] 

机构地区：[1]公安部第一研究所,北京100048 [2]北京大学数学科学学院,北京100871

出　　处：《CT理论与应用研究（中英文）》2010年第4期11-17,共7页Computerized Tomography Theory and Applications

基　　金：国家科技支撑计划课题(2009BAK64B02)

摘　　要：鉴于实际工程应用需求,基于截断投影数据的CT图像局部重建是X射线CT重建的一个重要课题,本文概述了现有的局部重建算法,分析了其优缺点,提出了一种基于改进重建滤波器的局部CT重建算法。通过对滤波函数的改进,使其能量主要集中在中心位置,使旁瓣迅速下降,进而使滤波函数具有局部重建功能。另外改进的滤波函数压制了低频信息,突出了高频信息,具有提高成像空间分辨率的功能,但对图像噪声有所放大,实际实验数据验证了算法的可行性。According to the requirement of practical engineering application,the image reconstruction based on truncated projection is one important problem in X-ray CT.The current local reconstruction algorithms are described and their advantages and disadvantages are analyzed.One local reconstruction algorithm based on improved reconstruction filter is proposed.Via the improvement of the filter,the energy of the filter function is centralized on the center position and its side band falls down quickly to make the filter function have local reconstruction feature.In addition,the improved filter,suppresses the low-frequency information and enhances high-frequency information,can enhance the imaging spatial resolution.While the proposed algorithm enlarges the noise of CT image more or less.The feasibility of the proposed algorithm is validated by the practical experiment data.

关 键 词：X射线 计算机断层成像 局部重建 滤波器 

分 类 号：TP391.41[自动化与计算机技术—计算机应用技术]